wftk::Region Class Reference

Region specifies a 'working area' of the screen - pixels outside the region are always ignored. More...

#include <region.h>

List of all members.

Public Types
enum	FillRule { EVEN_ODD_RULE, WINDING_RULE }
	Fill rule for polygons. More...
enum	OverlapType { OVERLAP_IN, OVERLAP_OUT, OVERLAP_PART }
	Types of overlapping between a rectangle and a region. More...
Public Member Functions
	Region ()
	Empty region.
	Region (const Region &)
	Copy a region.
	Region (const std::vector< Point >, FillRule)
	Region from polygon.
	Region (const SDL_Rect &)
	Region from rectangle.
	Region (const Point &)
	Region from point.
Region &	operator= (const Region &)
	copy one region into another
Rect	getClipbox () const
	Get clipping box.
RectList	getRectangles () const
	Get component rectangles.
unsigned long	nRects () const
Rect	getRect (unsigned long i) const
bool	empty () const
	true if region empty
bool	operator== (const Region &) const
	compare two regions
bool	operator!= (const Region &r) const
	compare two regions
bool	operator< (const Region &) const
	for std::map only
bool	contains (const Point &) const
	check if a region contains a point
OverlapType	overlap (const SDL_Rect &) const
	Check if a region contains/overlaps a rectangle.
void	clear ()
	set the region to be empty
void	offset (int dx, int dy)
	Move a region.
void	offset (const Point &p)
	Move a region.
void	shrink (int dx, int dy)
	Shrink a region Contract (dx, dy > 0) or expand (dx, dy < 0) the region in the directions of the axes.
Region &	operator|= (const Region &)
	Pointwise or.
Region &	operator &= (const Region &)
	Pointwise and.
Region &	operator-= (const Region &)
	Pointwise subtraction.
Region &	operator^= (const Region &)
	Pointwise xor.
Region	boundary (bool inside) const
	inside == true => points in the region which are next to points outside the region inside == false => points outside the region which are next to points in the region
const_iterator	begin () const
const_iterator	end () const
Friends
Region	operator| (const Region &r, const Region &r2)
	Pointwise or.
Region	operator & (const Region &r, const Region &r2)
	Pointwise and.
Region	operator- (const Region &r, const Region &r2)
	Pointwise subtraction.
Region	operator^ (const Region &r, const Region &r2)
	Pointwise xor.
Classes
class	const_iterator
	Iterator over points in the region. More...
class	RectList
	Used for things like passing an array of SDL_Rect to SDL_UpdateRects(). More...

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Detailed Description

Region specifies a 'working area' of the screen - pixels outside the region are always ignored.

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Member Enumeration Documentation

enum wftk::Region::FillRule

Fill rule for polygons. Enumeration values: EVEN_ODD_RULE  WINDING_RULE

enum wftk::Region::OverlapType

Types of overlapping between a rectangle and a region. Enumeration values: OVERLAP_IN  rectangle is in region OVERLAP_OUT  rectangle is not in region OVERLAP_PART  rectangle is partially in region

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Constructor & Destructor Documentation

Region::Region (  const Region &  region  )

Copy a region. Copies , creating an identical new region. Return value: a new region identical to

Region::Region (  const SDL_Rect &  rectangle  )

Region from rectangle. Creates a new region containing the area . Return value: a new region

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Member Function Documentation

Region Region::boundary (  bool  inside  )  const

inside == true => points in the region which are next to points outside the region inside == false => points outside the region which are next to points in the region FIXME pick a default value for 'inside'

Region::RectList Region::getRectangles (   )  const

Get component rectangles. Obtains the area covered by the region as a list of rectangles. The array returned in must be freed with g_free().

Region & Region::operator &= (  const Region &  other  )

Pointwise and. Sets the area of to the intersection of the areas of and . The resulting area is the set of pixels contained in both and .

Region & Region::operator-= (  const Region &  other  )

Pointwise subtraction. Subtracts the area of from the area . The resulting area is the set of pixels contained in but not in .

Region & Region::operator^= (  const Region &  other  )

Pointwise xor. Sets the area of to the exclusive-OR of the areas of and . The resulting area is the set of pixels contained in one or the other of the two sources but not in both.

Region & Region::operator|= (  const Region &  other  )

Pointwise or. Sets the area of to the union of the areas of and . The resulting area is the set of pixels contained in either or .

void Region::shrink (  int  dx, int  dy )

Shrink a region Contract (dx, dy > 0) or expand (dx, dy < 0) the region in the directions of the axes. If one of (dx, dy) is positive and the other negative, the region contracts in one direction and expands in the other.

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The documentation for this class was generated from the following files:

• region.h
• polyreg-generic.cpp
• region-generic.cpp

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Generated Tue Apr 12 22:48:55 2005.
Copyright © 1998-2003 by the respective authors.

This document is licensed under the terms of the GNU Free Documentation License and may be freely distributed under the conditions given by this license.